Search Results

Search found 28957 results on 1159 pages for 'single instance'.

Page 48/1159 | < Previous Page | 44 45 46 47 48 49 50 51 52 53 54 55  | Next Page >

• How do I dynamically define an instance variable?

  - by Moses

  Hi everyone, I have two classes (class1 and class2) that just store data, no methods. I have a third class that has an instance variable that, depending on some user input, will be set to one of the two classes. So, in the third class I declare the variable generically as NSObject *aClass; and during runtime set it to whatever it should be. aClass = [[Class1 alloc] init]; // or aClass = [[Class2 alloc] init]; However, when I try to access fields from aClass NSString *str = aClass.field1; It gives me the error: request for member 'field1' in something not a structure or a union. Field1 is declared in both class1 and class2. When I try to cast aClass aClass = (Class1 *) aClass; it gives the same error. What am I doing wrong, is there a better way to do this?

  Read the article

• What's the Difference Between These Two Ruby Class Initialization Definitions?

  - by michaelmichael

  I'm working through a book on Ruby, and the author used a slightly different form for writing a class initialization definition than he has in previous sections of the book. It looks like this: class Ticket attr_accessor :venue, :date def initialize(venue, date) self.venue = venue self.date = date end end In previous sections of the book, it would've been defined like this: class Ticket attr_accessor :venue, :date def initialize(venue, date) @venue = venue @date = date end end Is there any functional difference between using the setter method, as in the first example, vs. using the instance variable as in the second? They both seem to work. Even mixing them up works: class Ticket attr_accessor :venue, :date def initialize(venue, date) @venue = venue self.date = date end end

  Read the article

• Create instance of generic type in Java?

  - by David Citron

  Is it possible to create an instance of a generic type in Java? I'm thinking based on what I've seen that the answer is "no" (due to type erasure), but I'd be interested if anyone can see something I'm missing: class SomeContainer<E> { E createContents() { return what??? } } EDIT: It turns out that Super Type Tokens could be used to resolve my issue, but it requires a lot of reflection-based code, as some of the answers below have indicated. I'll leave this open for a little while to see if anyone comes up with anything dramatically different than Ian Robertson's Artima Article.

  Read the article

• Objective C instance variables - Newbie

  - by Dwayne King

  OK - so I'm sure my confusion here is just a result of being stuck in a "Java mindset" and not understanding how Obj C differs in this case. In Java, I can declare a variable in a class, like this, and each instance of that class will have it's own: MyClass { String myVar; MyClass() { // constructor } } In Obj C I tried to do the same thing by declaring a variable only in the .m file like this: #import "MyClass.h" @implementation MyClass NSString *testVar; @end My expectation here was that this variable has a scope limited to this class. So I created a second class (identical): #import "MySecondClass.h" @implementation MySecondClass NSString *testVar; @end What I'm seeing (and has me baffled) is that changing the variable in one class, affects the value seen in the other class. In fact, if I set a breakpoint, and then "Jump to Definition" of the variable, it takes me to th I've created an extremely small XCode project that demonstrates the problem here Nothing more humbling than moving to a new language :) Thanks in advance.

  Read the article

• Java: Friendlier way to get an instance of FontMetrics

  - by Martijn Courteaux

  Hi people, Is there a friendlier way to get an instance of FontMetrics than FontMetrics fm = Graphics.getFontMetrics(Font); I hate this way because of the following example: If you want to create in a game a menu and you want all the menuitems in the center of the screen you need fontmetrics. But, mostly, menuitems are clickable. So I create an array of Rectangles and all the rectangles fits around the items, so when the mouse is pressed, I can simply use for (int i = 0; i < rects.length; i++) if (rects[i].contains(mouseX, mouseY)) { ... } But to create the rects I also need FontMetrics for their coordinates. So this mean that I have to construct all my rectangles in the paint-method of my menu. So I want a way to get the FontMetrics so I can construct the Rectangles in a method called by the constructor. Hope you understand. Thanks in advance.

  Read the article

• Jquery scroll to first instance of a class (.error) for jquerytools validator

  - by Tommy Arnold

  I am using jquerytools validator on a clients website but the page using this plugin is very long so I would like to add a custom handler using the folowing code. $("#form").bind("onFail", function(e, errors) { // we are only doing stuff when the form is submitted if (e.originalEvent.type == 'submit') { $(".errormsg").html("Please scroll up and fix the highlighted errors."); //alert("Please fix the highlighted errors to continue"); } }); How would I get it to scroll up to the first instance of .error? Can you recommend any plugins for this?

  Read the article

• WPF Creating an instance of a class in xaml

  - by Cloverness

  Hi, I have a problem with creating the instance of a class in xaml file. I thought you can do it like this: in the resource part of the user control and then use it in the xaml file (for example bind to it). But even tough the class I created is located in the same namespace it says that: "The type was not found. Verfiy that all assemblies were built, etc". How to get it right? is there another method? Thanks for suggestions.

  Read the article

• Application.Current changes when using reflection to create an instance of another Application class

  - by markti

  Let's say I have the following Silverlight Applications: App1.xap App2.xap App3.xap Let's say that I start App1.xap as the default xap file. If I load App2.xap and App3.xap and instantiate an Application class within one of the other two XAPs. The Application.Current changes to be that new instance. System.Windows.Application obj = Activator.CreateInstance(type) as System.Windows.Application; I don't want the current application to change. I just want to get the merged Resource Dictionaries off the Application class.

  Read the article

• Logging on to two sites simultaneously

  - by James Wakefield

  I want to log on to two sites simultaneously to enable a single sign on solution. We have a smallish wiki that is created with Apple wiki and we have an intranet site on a aspx cms system by Elcom. Both use Active Directory for credentials. Currently they are on different domains, but we could enable a rewrite using our load-balancer (Citrix Netscaler) or IIS. These sites are on different servers, one a mysterious Mac system and the other an IIS v6.0 on windows 2003. Now I am almost certain that a reverse proxy set up will solve this but I really just need someone to agree that this solves this issue, and if there are things I should look out for what they might be. I just want to have an invisible log on screen in an iframe and enter clone the user name and password using javascript.

  Read the article

• Object reference not set to an instance of an object

  - by Ste

  I have this function that create runtime textbox: int i = 0; private TextBox[] addressBox = new TextBox[100]; private void appendNewTab() { addressBox[i] = new TextBox(); addressBox[i].KeyPress += new KeyPressEventHandler(this.addressBox_KeyPress); i++; } void addressBox_KeyPress(object sender, KeyPressEventArgs e) { if (e.KeyChar == (char)13) { MessageBox.Show(addressBox[i].Text); } } but i have Object reference not set to an instance of an object here MessageBox.Show(addressBox[i].Text); any suggestion?

  Read the article

• Obj-C memory management for an NSView * instance variable

  - by massimoperi

  My custom view has a subview as an instance variable. Here is a sample interface: @interface MyCustomView : NSView { NSView *aSubview; } @end Then, in the .m file, I initialize aSubView and add it to the custom view. - (id)init { self = [super initWithFrame:CGRectMakeFrame(0.0, 0.0, 320.0, 480.0); if (self) { aSubview = [[NSView alloc] initWithFrame(0.0, 0.0, 100.0, 100.0); [self addSubview:aSubview]; } return self; } Where should I release aSubView? In the -dealloc method? - (void)dealloc { [aSubView release]; [super dealloc]; } Or directly after adding it to the custom view in the -init method? - (id)init { [...] [self addSubview:aSubview]; [aSubview release]; [...] } Which one is the best implementation?

  Read the article

• Singelton restricted to instance of dll

  - by codeySmurf

  If I create a singleton class in the context of a dll, the singleton class is instantiated once and used by all instances of the dll. I am using a dll as a plug-in for an application. Now the following thing came to my mind: If I use a singleton Class, it will be shared across multiple instances of the plug-in. However, this makes it difficult to manage the lifetime of the singleton class efficiently. The only way I could think of would be to use a reference count and to make the singleton delete its self when the reference count is 0. Does anyone have any better ideas on that? Is there any good way to restrict the singleton object to one instance of the dll? Language is c++

  Read the article

• Creating an instance in rails association

  - by Sandeep Rao

  I have three models where a basiccase has a form. Basic case can create a new form. class User < ActiveRecord::Base has_many :basiccases end class Basiccase < ActiveRecord::Base belongs_to :user has_one :basiccases end class Form3C < ActiveRecord::Base belongs_to :basiccases end I want to create an instance of form 3c in the form3c controller. Can any one explain me how I can carry the basiccase_id to the form3c controller to set the foreign key attribute. I can set the value using @basiccase.build_form3_c but I'm not sure how I can get the basiccase_id from the basiccase.

  Read the article

• C# Making private instance variable accesable (jagged array)

  - by Chris

  Hello, In a attempt to put some more oop in a program i am looking to make a private instance variable in one class (object) accesable to a class. private byte [][] J; All those code refers to this jagged array with this. Now in the other class i putted all the for loops along with the consolewritlines to display the wanted results. Basicly it says "the name J does not exist in the current context" But how exactly do i make this J accesable? I have tried with get and set but i keep getting 'cannot convert to byte to byte[][]' Also what kind of cyntax would i need with get and set? Something along like this? Or would i need several more steps? : public Byte JArray get { return J; } //can converrt to byte here set { J = value; } //cannnot convert to byte here Kind regards

  Read the article

• TypeError: object not callable when making instance

  - by TSM

  I've searched around other threads with similar questions, but I'm not finding the answer. Basically, I have a class: import Android_Class class Android_Revision(object): def __init__(self): # dict for storing the classes in this revision # (format {name : classObject}): self.Classes = {} self.WorkingClass = Android_Class() self.RevisionNumber = '' def __call__(self): print "Called" def make_Class(self, name): newClass = Android_Class(name) self.Classes.update({name : newClass}) self.WorkingClass = newClass def set_Class(self, name): if not(self.Classes.has_key(name)): newClass = Android_Class(name) self.Classes.update({name : newClass}) self.WorkingClass = self.Classes.get(name) I'm trying to make an instance of this class: Revision = Android_Revision() and that's when I'm getting the error. I'm confused because I have another situation where I'm doing almost the exact same thing, and it's working fine. I can't figure out what differences between the two would lead to this error. Thanks.

  Read the article

• Are instance initializers good or bad?

  - by berry120

  I personally quite like instance initializers - I use them to assign default values to things such as collections so when writing constructors I don't have to remember to assign them the same default values each time. It seems quite elegant to me - avoids annoying NPE's popping up and avoids duplicate code. A private method doesn't seem as nice because a) it can't assign values to final fields, b) it could be run elsewhere in code and c) the method still needs to be explicitly called at the start of each constructor. However, the flip side with others I have spoken to is that they're confusing, some people reading the code might not understand what they do or when they're called and thus they could cause more problems than they solve. Are proper use of these initializers something to be encouraged or avoided? Or is it an "each to their own" case?

  Read the article

• Load custom class properly

  - by LinusAn

  I have a custom class which I want to "load" inside the firstViewController and then access it from other classes by segues. My Problem is, I can't even access and change the instance variable inside the firstViewController. Somehow I'm "loading" it wrong. Here is the code I used until now: inside viewController.h @property (strong, nonatomic) myClass *newClass; inside viewController.m @synthesize newClass; I then try to access it by: self.newClass.string = @"myString"; if(newClass.string == @"myString"){ NSLog(@"didn't work"); } Well, I get "didn't work". Why is that? When I write myClass *newClass = [myClass new]; It does work. But the class and its properties gets overwritten every time the ViewController loads again. What would you recommend? Thank you very much.

  Read the article

• Error Installing ruby with RVM Single User mode on Arch Linux

  - by ChrisBurnor

  I've just installed RVM on ArchLinux x64 in single user mode via the recommended install script curl -L https://get.rvm.io | bash -s stable I've also installed all the requirements listed in rvm requirements However, I'm having trouble actually installing any version of ruby. And getting the following error: arch:~ % rvm install 1.9.3 No binary rubies available for: ///ruby-1.9.3-p194. Continuing with compilation. Please read 'rvm mount' to get more information on binary rubies. Fetching yaml-0.1.4.tar.gz to /home/christopher/.rvm/archives % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 100 460k 100 460k 0 0 702k 0 --:--:-- --:--:-- --:--:-- 767k Extracting yaml-0.1.4.tar.gz to /home/christopher/.rvm/src Prepare yaml in /home/christopher/.rvm/src/yaml-0.1.4. Configuring yaml in /home/christopher/.rvm/src/yaml-0.1.4. Error running ' ./configure --prefix=/home/christopher/.rvm/usr ', please read /home/christopher/.rvm/log/ruby-1.9.3-p194/yaml/configure.log Compiling yaml in /home/christopher/.rvm/src/yaml-0.1.4. Error running 'make', please read /home/christopher/.rvm/log/ruby-1.9.3-p194/yaml/make.log Please note that it's required to reinstall all rubies: rvm reinstall all --force Installing Ruby from source to: /home/christopher/.rvm/rubies/ruby-1.9.3-p194, this may take a while depending on your cpu(s)... ruby-1.9.3-p194 - #downloading ruby-1.9.3-p194, this may take a while depending on your connection... ruby-1.9.3-p194 - #extracting ruby-1.9.3-p194 to /home/christopher/.rvm/src/ruby-1.9.3-p194 ruby-1.9.3-p194 - #extracted to /home/christopher/.rvm/src/ruby-1.9.3-p194 Skipping configure step, 'configure' does not exist, did autoreconf not run successfully? ruby-1.9.3-p194 - #compiling Error running 'make', please read /home/christopher/.rvm/log/ruby-1.9.3-p194/make.log There has been an error while running make. Halting the installation. The log files are as follows: arch:~ % cat ~/.rvm/log/ruby-1.9.3-p194/yaml/configure.log __rvm_log_command:32: permission denied: arch:~ % cat ~/.rvm/log/ruby-1.9.3-p194/yaml/make.log make: *** No targets specified and no makefile found. Stop. arch:~ % cat ~/.rvm/log/ruby-1.9.3-p194/make.log make: *** No targets specified and no makefile found. Stop.

  Read the article

• Moving Windows XP from ICH10R RAID 5 to single disk using Linux [migrated]

  - by tudor

  A friend's machine running Windows XP refused to boot recently which is running 3 SATA disks on RAID 5 (which was previously upgraded from RAID 1 not by me). I have determined there to be a disk failure. The disks have been replaced many times in the past few years. I wish to backup the RAID5 partition before I try anything to fix it. The RAID chipset used is ICH10R/DO. So, I plugged in an extra IDE drive and an Ubuntu USB key and looked at the RAID. The partitioning is a mess, but I did find at least one degraded but working RAID array with two partitions, one 79GB and the other 86GB. Then I: 1) Partitioned my IDE disk using fdisk to have a partition of 80GB and bootable, and marked as NTFS. 2) dd the contents of the array to the partition 3) disconnected everything else 4) inserted a Windows XP CD and ran fixboot, fixmbr, and bootcfg. They all run ok and claim that they worked. (e.g. bootcfg detects the Windows partition, fixboot returns saying that it was written correctly.) However, I'm still getting an error like "DISK FAILURE, BOOT DISK NOT FOUND". I have tried running the GRUB rescue disk, which also runs ok, but won't boot into Windows. It just stops with a flashing cursor after chainloader +1, boot. One clue may be that the partitions appear to be wack. One disk has a 79GB RAID partition on a 500GB drive with a offset, the second disk has a 320GB RAID partition across the whole drive. Additionally, the BIOS lists the RAID size as being 149GB. I don't see how this works. How are they even assembling the array when the partitions are so different? I have also tried running the Windows XP automated repair tool, but that didn't work either. I'm presuming this is something simple. Perhaps Windows is attempting to boot into RAID and, upon not finding it, simply crashing? Perhaps the 79GB partitions offset means that it's looking into the disk by that much? Please help!! To clarify: I want to make the single IDE disk bootable with a copy of the array so that I can prove/disprove that it's just that Windows has become corrupted, and use windows tools to correct it before attempting the same thing on the RAID array. That way I have a working backup and can show the process I used to fix it.

  Read the article

• Encoding multiple video streams with a single avconv invocation

  - by automatthias

  I played with avconv on Ubuntu and I'm now able to e.g. record the desktop with sound from a soundcard. One thing I wanted to do was recording two video inputs at the same time, for instance the desktop and from the webcam. I thought about doing something like this: avconv \ -f alsa \ -i default \ -acodec flac \ -f video4linux2 \ -r 6 \ -i /dev/video0 \ -f x11grab \ -i :0.0 \ out.mkv My thinking was that if you define multiple video inputs, and the .mkv format can handle multiple video streams, avconv will encode 2 video streams and 1 audio stream into one file. But this isn't what happens: avconv version 0.8.4-6:0.8.4-0ubuntu0.12.10.1, Copyright (c) 2000-2012 the Libav developers built on Nov 6 2012 16:51:11 with gcc 4.7.2 [alsa @ 0x1091bc0] capture with some ALSA plugins, especially dsnoop, may hang. [alsa @ 0x1091bc0] Estimating duration from bitrate, this may be inaccurate Input #0, alsa, from 'default': Duration: N/A, start: 1354364317.020350, bitrate: N/A Stream #0.0: Audio: pcm_s16le, 48000 Hz, 2 channels, s16, 1536 kb/s [video4linux2 @ 0x10923e0] Estimating duration from bitrate, this may be inaccurate Input #1, video4linux2, from '/dev/video0': Duration: N/A, start: 100607.724745, bitrate: 29491 kb/s Stream #1.0: Video: rawvideo, yuyv422, 640x480, 29491 kb/s, 6 tbr, 1000k tbn, 6 tbc [x11grab @ 0x107b2a0] device: :0.0+83,87 -> display: :0.0 x: 83 y: 87 width: 854 height: 480 [x11grab @ 0x107b2a0] shared memory extension found [x11grab @ 0x107b2a0] Estimating duration from bitrate, this may be inaccurate Input #2, x11grab, from ':0.0+83,87': Duration: N/A, start: 1354364318.488382, bitrate: 196761 kb/s Stream #2.0: Video: rawvideo, bgra, 854x480, 196761 kb/s, 15 tbr, 1000k tbn, 15 tbc Incompatible pixel format 'bgra' for codec 'mpeg4', auto-selecting format 'yuv420p' [buffer @ 0x107fcc0] w:854 h:480 pixfmt:bgra [avsink @ 0x10bdf00] auto-inserting filter 'auto-inserted scaler 0' between the filter 'src' and the filter 'out' [scale @ 0x10dc680] w:854 h:480 fmt:bgra -> w:854 h:480 fmt:yuv420p flags:0x4 Output #0, matroska, to '.../out.mkv': Metadata: encoder : Lavf53.21.0 Stream #0.0: Video: mpeg4, yuv420p, 854x480, q=2-31, 4000 kb/s, 1k tbn, 15 tbc Stream #0.1: Audio: libvorbis, 48000 Hz, 2 channels, s16 Stream mapping: Stream #2:0 -> #0:0 (rawvideo -> mpeg4) Stream #0:0 -> #0:1 (pcm_s16le -> libvorbis) Press ctrl-c to stop encoding [mpeg4 @ 0x10bd800] rc buffer underflow ^Cframe= 160 fps= 15 q=2.0 Lsize= 3414kB time=10.66 bitrate=2623.0kbits/s video:3273kB audio:131kB global headers:4kB muxing overhead 0.165600% Received signal 2: terminating. I'm not sure if it's the question of mapping (some -map options to add?) or that avconv just can't encode more than 1 video stream at one time. So is it an actual avconv limitation, or a limitation of the available containers, or me simply not finding the right combination of command line options?

  Read the article

• Single line diff

  - by Ollie Saunders

  Is there a diff tool I can run from the command line or maybe just an online webpage that will compare single lines? GitHub diffs do this but I'm don't want to publish things to GitHub just to read the diffs! This is the sort of thing I'm wanting to diff: a:2:{i:0;O:10:"FuTreeNode":6:{s:5:"outer";r:2;s:6:"inners";O:20:"FuLinkedTreeNodeList":2:{s:5:"outer";r:2;s:5:"items";a:0:{}}s:5:"value";s:3:"foo";s:4:"next";O:10:"FuTreeNode":6:{s:5:"outer";r:2;s:6:"inners";O:20:"FuLinkedTreeNodeList":2:{s:5:"outer";r:8;s:5:"items";a:0:{}}s:5:"value";s:3:"bar";s:4:"next";N;s:4:"prev";O:10:"FuTreeNode":6:{s:5:"outer";N;s:6:"inners";O:20:"FuLinkedTreeNodeList":2:{s:5:"outer";r:15;s:5:"items";a:0:{}}s:5:"value";s:3:"zim";s:4:"next";r:8;s:4:"prev";O:10:"FuTreeNode":6:{s:5:"outer";N;s:6:"inners";O:20:"FuLinkedTreeNodeList":2:{s:5:"outer";r:22;s:5:"items";a:0:{}}s:5:"value";s:3:"foo";s:4:"next";r:15;s:4:"prev";r:8;s:6:"ofList";O:12:"FuLinkedList":1:{s:5:"items";a:4:{i:0;r:2;i:1;r:8;i:2;r:22;i:3;r:15;}}}s:6:"ofList";r:30;}s:6:"ofList";O:20:"FuLinkedTreeNodeList":2:{s:5:"outer";r:2;s:5:"items";a:2:{i:0;r:2;i:1;r:8;}}}s:4:"prev";N;s:6:"ofList";r:37;}i:1;r:8;} a:2:{i:0;O:10:"FuTreeNode":6:{s:5:"outer";r:2;s:6:"inners";O:20:"FuLinkedTreeNodeList":2:{s:5:"outer";r:2;s:5:"items";a:0:{}}s:5:"value";s:3:"foo";s:4:"next";O:10:"FuTreeNode":6:{s:5:"outer";r:2;s:6:"inners";O:20:"FuLinkedTreeNodeList":2:{s:5:"outer";r:8;s:5:"items";a:0:{}}s:5:"value";s:3:"bar";s:4:"next";N;s:4:"prev";O:10:"FuTreeNode":6:{s:5:"outer";N;s:6:"inners";O:20:"FuLinkedTreeNodeList":2:{s:5:"outer";r:15;s:5:"items";a:0:{}}s:5:"value";s:3:"zim";s:4:"next";r:8;s:4:"prev";O:10:"FuTreeNode":6:{s:5:"outer";N;s:6:"inners";O:20:"FuLinkedTreeNodeList":2:{s:5:"outer";r:22;s:5:"items";a:0:{}}s:5:"value";s:3:"foo";s:4:"next";r:15;s:4:"prev";r:8;s:6:"ofList";O:12:"FuLinkedList":1:{s:5:"items";a:4:{i:0;r:2;i:1;r:8;i:2;r:22;i:3;r:15;}}}s:6:"ofList";r:30;}s:6:"ofList";O:20:"FuLinkedTreeNodeList":2:{s:5:"outer";r:2;s:5:"items";a:2:{i:0;r:2;i:1;r:8;}}}s:4:"prev";N;s:6:"ofList";r:37;}i:1;r:22;} I'm on Mac OS X.

  Read the article

• Network communications mechanisms for SQL Server

  - by Akshay Deep Lamba

  Problem I am trying to understand how SQL Server communicates on the network, because I'm having to tell my networking team what ports to open up on the firewall for an edge web server to communicate back to the SQL Server on the inside. What do I need to know? Solution In order to understand what needs to be opened where, let's first talk briefly about the two main protocols that are in common use today: TCP - Transmission Control Protocol UDP - User Datagram Protocol Both are part of the TCP/IP suite of protocols. We'll start with TCP. TCP TCP is the main protocol by which clients communicate with SQL Server. Actually, it is more correct to say that clients and SQL Server use Tabular Data Stream (TDS), but TDS actually sits on top of TCP and when we're talking about Windows and firewalls and other networking devices, that's the protocol that rules and controls are built around. So we'll just speak in terms of TCP. TCP is a connection-oriented protocol. What that means is that the two systems negotiate the connection and both agree to it. Think of it like a phone call. While one person initiates the phone call, the other person has to agree to take it and both people can end the phone call at any time. TCP is the same way. Both systems have to agree to the communications, but either side can end it at any time. In addition, there is functionality built into TCP to ensure that all communications can be disassembled and reassembled as necessary so it can pass over various network devices and be put together again properly in the right order. It also has mechanisms to handle and retransmit lost communications. Because of this functionality, TCP is the protocol used by many different network applications. The way the applications all can share is through the use of ports. When a service, like SQL Server, comes up on a system, it must listen on a port. For a default SQL Server instance, the default port is 1433. Clients connect to the port via the TCP protocol, the connection is negotiated and agreed to, and then the two sides can transfer information as needed until either side decides to end the communication. In actuality, both sides will have a port to use for the communications, but since the client's port is typically determined semi-randomly, when we're talking about firewalls and the like, typically we're interested in the port the server or service is using. UDP UDP, unlike TCP, is not connection oriented. A "client" can send a UDP communications to anyone it wants. There's nothing in place to negotiate a communications connection, there's nothing in the protocol itself to coordinate order of communications or anything like that. If that's needed, it's got to be handled by the application or by a protocol built on top of UDP being used by the application. If you think of TCP as a phone call, think of UDP as a postcard. I can put a postcard in the mail to anyone I want, and so long as it is addressed properly and has a stamp on it, the postal service will pick it up. Now, what happens it afterwards is not guaranteed. There's no mechanism for retransmission of lost communications. It's great for short communications that doesn't necessarily need an acknowledgement. Because multiple network applications could be communicating via UDP, it uses ports, just like TCP. The SQL Browser or the SQL Server Listener Service uses UDP. Network Communications - Talking to SQL Server When an instance of SQL Server is set up, what TCP port it listens on depends. A default instance will be set up to listen on port 1433. A named instance will be set to a random port chosen during installation. In addition, a named instance will be configured to allow it to change that port dynamically. What this means is that when a named instance starts up, if it finds something already using the port it normally uses, it'll pick a new port. If you have a named instance, and you have connections coming across a firewall, you're going to want to use SQL Server Configuration Manager to set a static port. This will allow the networking and security folks to configure their devices for maximum protection. While you can change the network port for a default instance of SQL Server, most people don't. Network Communications - Finding a SQL Server When just the name is specified for a client to connect to SQL Server, for instance, MySQLServer, this is an attempt to connect to the default instance. In this case the client will automatically attempt to communicate to port 1433 on MySQLServer. If you've switched the port for the default instance, you'll need to tell the client the proper port, usually by specifying the following syntax in the connection string: <server>,<port>. For instance, if you moved SQL Server to listen on 14330, you'd use MySQLServer,14330 instead of just MySQLServer. However, because a named instance sets up its port dynamically by default, the client never knows at the outset what the port is it should talk to. That's what the SQL Browser or the SQL Server Listener Service (SQL Server 2000) is for. In this case, the client sends a communication via the UDP protocol to port 1434. It asks, "Where is the named instance?" So if I was running a named instance called SQL2008R2, it would be asking the SQL Browser, "Hey, how do I talk to MySQLServer\SQL2008R2?" The SQL Browser would then send back a communications from UDP port 1434 back to the client telling the client how to talk to the named instance. Of course, you can skip all of this of you set that named instance's port statically. Then you can use the <server>,<port> mechanism to connect and the client won't try to talk to the SQL Browser service. It'll simply try to make the connection. So, for instance, is the SQL2008R2 instance was listening on port 20080, specifying MySQLServer,20080 would attempt a connection to the named instance. Network Communications - Named Pipes Named pipes is an older network library communications mechanism and it's generally not used any longer. It shouldn't be used across a firewall. However, if for some reason you need to connect to SQL Server with it, this protocol also sits on top of TCP. Named Pipes is actually used by the operating system and it has its own mechanism within the protocol to determine where to route communications. As far as network communications is concerned, it listens on TCP port 445. This is true whether we're talking about a default or named instance of SQL Server. The Summary Table To put all this together, here is what you need to know: Type of Communication Protocol Used Default Port Finding a SQL Server or SQL Server Named Instance UDP 1434 Communicating with a default instance of SQL Server TCP 1433 Communicating with a named instance of SQL Server TCP * Determined dynamically at start up Communicating with SQL Server via Named Pipes TCP 445

  Read the article

• StructureMap Exception Code: 202 No Default Instance defined for PluginFamily

  - by Code Sherpa

  Hi. I am new to StructureMap. I have downloaded and am using version 2.6.1.0. I keep getting the below error: StructureMap Exception Code: 202 No Default Instance defined for PluginFamily Company.ProjectCore.Core.IConfiguration, Company.ProjectCore, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null My Global.asax.cs looks like: protected void Application_Start(object sender, EventArgs e) { var container = new Container(x => { x.For<ICache>().Use<Cache>(); x.For<IEmailService>().Use<EmailService>(); x.For<IUserSession>().Use<UserSession>(); x.For<IRedirector>().Use<Redirector>(); x.For<INavigation>().Use<Navigation>(); }); container.AssertConfigurationIsValid(); } I changed from ObjectFactory.Initialize to "new Container" to debug. When stepping through the AssertConfigurationIsValid() method, Cache works but EmailService fails at the GetInstance method in the following line: private readonly IConfiguration _configuration; public EmailService() { _configuration = ObjectFactory.GetInstance<IConfiguration>(); } If I remove IEmailService, the same 202 error is thrown at IUserSession. Should I be adding something else in Application_Start or in my class files? Thanks in advance...

  Read the article

• sort django queryset by latest instance of a subset of related model

  - by rsp

  I have an Order model and order_event model. Each order_event has a foreignkey to order. so from an order instance i can get: myorder.order_event_set. I want to get a list of all orders but i want them to be sorted by the date of the last event. A statement like this works to sort by the latest event date: queryset = Order.objects.all().annotate(latest_event_date=Max('order_event__event_datetime')).order_by('latest_event_date') However, what I really need is a list of all orders sorted by latest date of A SUBSET OF EVENTS. For example my events are categorized into "scheduling", "processing", etc. So I should be able to get a list of all orders sorted by the latest scheduling event. This django doc (https://docs.djangoproject.com/en/dev/topics/db/aggregation/#filter-and-exclude) shows how I can get the latest schedule event using a filter but this excludes orders without a scheduling event. I thought I could combine the filtered queryset with a queryset that includes back those orders that are missing a scheduling event...but I'm not quite sure how to do this. I saw answers related to using python list but it would be much more useful to have a proper django queryset (ie for a view with pagination, etc.)

  Read the article

• CKEditor instance already exists

  - by jackboberg

  I am using jquery dialogs to present forms (fetched via AJAX). On some forms I am using a CKEditor for the textareas. The editor displays fine on the first load. When the user cancels the dialog, I am removing the contents so that they are loaded fresh on a later request. The issue is, once the dialog is reloaded, the CKEditor claims the editor already exists. uncaught exception: [CKEDITOR.editor] The instance "textarea_name" already exists. The API includes a method for destroying existing editors, and I have seen people claiming this is a solution: if (CKEDITOR.instances['textarea_name']) { CKEDITOR.instances['textarea_name'].destroy(); } CKEDITOR.replace('textarea_name'); This is not working for me, as I receive a new error instead: TypeError: Result of expression 'i.contentWindow' [null] is not an object. This error seems to occur on the "destroy()" rather than the "replace()". Has anyone experienced this and found a different solution? Is is possible to 're-render' the existing editor, rather than destroying and replacing it? UPDATED Here is another question dealing with the same problem, but he has provided a downloadable test case.

  Read the article

< Previous Page | 44 45 46 47 48 49 50 51 52 53 54 55  | Next Page >